Like the look of this a lot. I'm a fan of mind maps for getting work done. I might suggest that unless you think that a large portion of your audience are vim users then you might use ijkl instead of hjkl. For a non-vim user ijkl is completely natural but hjkl will be annoying.
You prefer they use something that 'feels' natural to you over a very commonly used pattern?
Left/Up/Down/Right on the same middle row is more intuitive than putting Up on a higher row IMO. On my thinkpad "i" is not centered above "k" (the way Up/Down arrow keys are aligned), it's offset over both "j" and "k", so when not looking at my keys while typing this will likely cause more errors.
I've personally never seen I/JKL before and over the years I've come to believe Vim made the right choice by use HJKL on the 'home row', so I might be biased. I can put my four fingers on all 4 keys at once with HJKL, but I can't with I/JKL.
This is a standard starting position (just shifted over one key left):
Up being to the right of Left and to the left of Down is intuitive to you? I'd say Up and Down being as their name suggests would be more intuitive....
